Medication delivery device

ABSTRACT

The present disclosure relates to a dose detection system for use in combination with a medication delivery device in which a dose setting member rotates relative to an actuator during dose delivery. The dose detection system includes a module which is removably attached to the medication delivery device. The module includes a dosing component attached to the actuator during dose delivery. The dosing component includes a light source and a light sensor. A sensed element is attached to the dose setting member and includes surface features detectable by the light sensor.

TECHNICAL FIELD

The present disclosure relates to an electronic dose detection systemfor a medication delivery device, and illustratively to an electronicdose detection module adapted to removably attach to a proximal endportion of a medication delivery device. The dose delivery detectionsystem is operable to detect the amount of a dose of medicationdelivered by the medication delivery device.

BACKGROUND

Patients suffering from various diseases must frequently injectthemselves with medication. To allow a person to conveniently andaccurately self-administer medicine, a variety of devices broadly knownas pen injectors or injection pens have been developed. Generally, thesepens are equipped with a cartridge including a piston and containing amulti-dose quantity of liquid medication. A drive member is movableforward to advance the piston in the cartridge to dispense the containedmedication from an outlet at the distal cartridge end, typically througha needle. In disposable or prefilled pens, after a pen has been utilizedto exhaust the supply of medication within the cartridge, a userdiscards the entire pen and begins using a new replacement pen. Inreusable pens, after a pen has been utilized to exhaust the supply ofmedication within the cartridge, the pen is disassembled to allowreplacement of the spent cartridge with a fresh cartridge, and then thepen is reassembled for its subsequent use.

Many pen injectors and other medication delivery devices utilizemechanical systems in which members rotate and/or translate relative toone another in a manner proportional to the dose delivered by operationof the device. Accordingly, the art has endeavored to provide reliablesystems that accurately measure the relative movement of members of amedication delivery device in order to assess the dose delivered. Suchsystems may include a sensor which is secured to a first member of themedication delivery device, and which detects the relative movement of asensed component secured to a second member of the device.

The administration of a proper amount of medication requires that thedose delivered by the medication delivery device be accurate. Many peninjectors and other medication delivery devices do not include thefunctionality to automatically detect and record the amount ofmedication delivered by the device during the injection event. In theabsence of an automated system, a patient must manually keep track ofthe amount and time of each injection. Accordingly, there is a need fora device that is operable to automatically detect the dose delivered bythe medication delivery device during an injection event. Further, thereis a need for such a dose detection device to be removable and reusablewith multiple delivery devices.

SUMMARY

In accordance with an aspect of the present disclosure, a dose detectionsystem is provided for a medication delivery device which includes adose setting member which rotates relative to an actuator during dosedelivery. The dose detection system comprises an electronics assemblyattached to the actuator and a sensed element attached to the dosesetting member. The electronics assembly includes a rotation sensoroperable with the sensed element to detect the movement of the dosesetting member relative to the actuator during dose delivery. Theelectronics assembly may further include various additional componentssuch as one or more other sensors, memory, a processor, a controller, abattery, etc.

In another aspect, the dose delivery detection system comprises a modulewhich is removably attachable to the medication delivery device. Amongother advantages, the attachable and detachable module is operative todetect a delivered medication amount without changing the functionalityor operation of the medication delivery device to which it is attached.In some embodiments, the sensing system records the size of thedelivered dose and communicates the information to an external device.The medication delivery device may include a medication. Otheradvantages will be recognized by those of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present disclosure will become moreapparent to those skilled in the art upon consideration of the followingdetailed description taken in conjunction with the accompanying figures.

FIG. 1 is a perspective view of an exemplary medication delivery devicewith which the dose detection system of the present disclosure isoperable.

FIG. 2 is a cross-sectional perspective view of the exemplary medicationdelivery device of FIG. 1 .

FIG. 3 is a perspective view of the proximal portion of the exemplarymedication delivery device of FIG. 1 .

FIG. 4 is a partially-exploded, perspective view of the proximal portionof the exemplary medication delivery device of FIG. 1 , and showing adose detection module.

FIG. 5 is a side, diagrammatic view, partially in cross section, of anexemplary embodiment of a dose detection system shown attached to theproximal portion of a medication delivery device.

FIG. 6 is a perspective view of a sensed element of the sensor system ofFIG. 5 .

FIG. 7 is a side, diagrammatic view, partially in cross section, of thedose detection system of FIG. 5 in the dose setting mode.

FIG. 8 shows the dose detection system of FIG. 7 with the module presseddistally as in the dose delivery mode.

FIG. 9 shows an alternate dose detection system involving the use ofreflected light.

FIG. 10 is a cross-sectional view showing another illustrativeembodiment of the dose detecting module installed on a medicationdelivery device.

FIG. 11 is a partial, cross-sectional view showing a sensor and sensedelement of another illustrative embodiment of the dose detection system.

FIG. 12 is a partial, cross-sectional view of the dose detection systemof FIG. 11 taken along line 12-12, and showing detection based onaxially transmitted light.

FIG. 13 is a partial cross-sectional view of an alternate embodiment tothat of FIG. 12 detecting reflected light.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the invention is thereby intended.

The present disclosure relates to sensing systems for medicationdelivery devices. In one aspect, the sensing system is for determiningthe amount of a dose delivered by a medication delivery device based onthe sensing of relative rotational movement between a dose settingmember and an actuator of the medication delivery device. The sensedrelative rotational movements are correlated to the amount of the dosedelivered. By way of illustration, the medication delivery device isdescribed in the form of a pen injector. However, the medicationdelivery device may be any device which is used to set and to deliver adose of a medication, such as a pen injector, an infusion pump or asyringe. The medication may be any of a type that may be delivered bysuch a medication delivery device.

Devices described herein, such as a device 10, may further comprise amedication, such as for example, within a reservoir or cartridge 20. Inanother embodiment, a system may comprise one or more devices includingdevice 10 and a medication. The term “medication” refers to one or moretherapeutic agents including but not limited to insulins, insulinanalogs such as insulin lispro or insulin glargine, insulin derivatives,GLP-1 receptor agonists such as dulaglutide or liraglutide, glucagon,glucagon analogs, glucagon derivatives, gastric inhibitory polypeptide(GIP), GIP analogs, GIP derivatives, oxyntomodulin analogs,oxyntomodulin derivatives, therapeutic antibodies and any therapeuticagent that is capable of delivery by the above device. The medication asused in the device may be formulated with one or more excipients. Thedevice is operated in a manner generally as described above by apatient, caregiver or healthcare professional to deliver medication to aperson.

An exemplary medication delivery device 10 is illustrated in FIGS. 1-4as a pen injector configured to inject a medication into a patientthrough a needle. Pen injector 10 includes a body 11 comprising anelongated, pen-shaped housing 12 including a distal portion 14 and aproximal portion 16. Distal portion 14 is received within a pen cap 18.Referring to FIG. 2 , distal portion 14 contains a reservoir orcartridge 20 configured to hold the medicinal fluid to be dispensedthrough its distal outlet end during a dispensing operation. The outletend of distal portion 14 is equipped with a removable needle assembly 22including an injection needle 24 enclosed by a removable cover 25. Apiston 26 is positioned in reservoir 20. An injecting mechanismpositioned in proximal portion 16 is operative to advance piston 26toward the outlet of reservoir 20 during the dose dispensing operationto force the contained medicine through the needled end. The injectingmechanism includes a drive member 28, illustratively in the form of ascrew, axially movable relative to housing 12 to advance piston 26through reservoir 20.

A dose setting member 30 is coupled to housing 12 for setting a doseamount to be dispensed by device 10. In the illustrated embodiment, dosesetting member 30 is in the form of a screw element operative to spiral(i.e., simultaneously move axially and rotationally) relative to housing12 during dose setting and dose dispensing. FIGS. 1 and 2 illustrate thedose setting member 30 fully screwed into housing 12 at its home or zerodose position. Dose setting member 30 is operative to screw out in aproximal direction from housing 12 until it reaches a fully extendedposition corresponding to a maximum dose deliverable by device 10 in asingle injection.

Referring to FIGS. 2-4 , dose setting member 30 includes a cylindricaldose dial member 32 having a helically threaded outer surface thatengages a corresponding threaded inner surface of housing 12 to allowdose setting member 30 to spiral relative to housing 12. Dose dialmember 32 further includes a helically threaded inner surface thatengages a threaded outer surface of sleeve 34 (FIG. 2 ) of device 10.The outer surface of dial member 32 includes dose indicator markings,such as numbers that are visible through a dosage window 36 to indicateto the user the set dose amount. Dose setting member 30 further includesa tubular flange 38 that is coupled in the open proximal end of dialmember 32 and is axially and rotationally locked to dose dial member 32by detents 40 received within openings 41 in dial member 32. Dosesetting member 30 further includes a collar or skirt 42 positionedaround the outer periphery of dial member 32 at its proximal end. Skirt42 is axially and rotationally locked to dial member 32 by tabs 44received in slots 46.

Dose setting member 30 therefore may be considered to comprise any orall of dose dial member 32, flange 38, and skirt 42, as they are allrotationally and axially fixed together. Dose dial member 32 is directlyinvolved in setting the dose and driving delivery of the medication.Flange 38 is attached to dial member 32 and, as described later,cooperates with a clutch to selectively couple dial member 32 with adose button. As shown, skirt 42 provides a surface external of body 11to enable a user to rotate dose dial member 32 for setting a dose.

Skirt 42 illustratively includes a plurality of surface contours 48 andan annular ridge 49 formed on the outer surface of skirt 42. Surfacecontours 48 are illustratively longitudinally extending ribs and groovesthat are circumferentially spaced around the outer surface of skirt 42and facilitate a user's grasping and rotating the skirt. In analternative embodiment, skirt 42 is removed or is integral with dialmember 32, and a user may grasp and rotate dose dial member 32 for dosesetting.

Delivery device 10 includes an actuator 50 having a clutch 52 which isreceived within dose dial member 32. Clutch 52 includes an axiallyextending stem 54 at its proximal end. Actuator 50 further includes dosebutton 56 positioned proximally of skirt 42 of dose setting member 30.Dose button 56 includes a mounting collar 58 (FIG. 2 ) centrally locatedon the distal surface of dose button 56. Collar 58 is attached to stem54 of clutch 52, such as with an interference fit or an ultrasonic weld,so as to axially and rotatably fix together dose button 56 and clutch52.

Dose button 56 includes a disk-shaped proximal end surface or face 60and an annular wall portion 62 extending distally and spaced radiallyinwardly of the outer peripheral edge of face 60 to form an annular lip64 there between. Face 60 of dose button 56 serves as a push surfaceagainst which a force can be applied manually, i.e., directly by theuser to push actuator 50 in a distal direction. Dose button 56illustratively includes a recessed portion 66 centrally located onproximal face 60, although proximal face 60 alternatively may be a flatsurface. A bias member 68, illustratively a spring, is disposed betweenthe distal surface 70 of button 56 and a proximal surface 72 of tubularflange 38 to urge actuator 50 and dose setting member 30 axially awayfrom each other. Dose button 56 is depressible by a user to initiate thedose dispensing operation.

Delivery device 10 is operable in both a dose setting mode and a dosedispensing mode. In the dose setting mode of operation, dose settingmember 30 is dialed (rotated) relative to housing 12 to set a desireddose to be delivered by device 10. Dialing in the proximal directionserves to increase the set dose, and dialing in the distal directionserves to decrease the set dose. Dose setting member 30 is adjustable inrotational increments (e.g., clicks) corresponding to the minimumincremental increase or decrease of the set dose during the dose settingoperation. For example, one increment or “click” may equal one-half orone unit of medication. The set dose amount is visible to the user viathe dial indicator markings shown through dosage window 36. Actuator 50,including dose button 56 and clutch 52, move axially and rotationallywith dose setting member 30 during the dialing in the dose setting mode.

Dose dial member 32, flange 38 and skirt 42 are all fixed rotationallyto one another, and rotate and extend proximally of the medicationdelivery device 10 during dose setting, due to the threaded connectionof dose dial member 32 with housing 12. During this dose setting motion,dose button 56 is rotationally fixed relative to skirt 42 bycomplementary splines 74 of flange 38 and clutch 52 (FIG. 2 ), which areurged together by bias member 68. In the course of dose setting, skirt42 and dose button 56 move relative to housing 12 in a spiral mannerfrom a “start” position to an “end” position. This rotation relative tothe housing is in proportion to the amount of dose set by operation ofthe medication delivery device 10. Alternatively, the device may beconfigured such that in the course of dose setting, skirt 42 and dosebutton 56 move only rotationally relative to housing 12 (that is,without spiraling out), and dose dispensing is initiating after dosesetting by applying axial force to the module coupled to dose button 56.

Once the desired dose is set, device 10 is manipulated so the injectionneedle 24 properly penetrates, for example, a user's skin. The dosedispensing mode of operation is initiated in response to an axial distalforce applied to the proximal face 60 of dose button 56. The axial forceis applied by the user directly to dose button 56. This causes axialmovement of actuator 50 in the distal direction relative to housing 12.

The axial shifting motion of actuator 50 compresses biasing member 68and reduces or closes the gap between dose button 56 and tubular flange38. This relative axial movement separates the complementary splines 74on clutch 52 and flange 38, and thereby disengages actuator 50, e.g.,dose button 56, from being rotationally fixed to dose setting member 30.In particular, dose setting member 30 is rotationally uncoupled fromactuator 50 to allow back driving rotation of dose setting member 30relative to actuator 50 and housing 12. Also, since dose setting member30 and actuator 50 are free to relatively rotate, actuator 50 is heldfrom rotating relative to device housing 12 by the user's engagement ofdose button 56 by pressing against it.

As actuator 50 is continued to be axially plunged without rotationrelative to housing 12, dial member 32 screws back into housing 12 as itspins relative to dose button 56. The dose markings that indicate theamount still remaining to be injected are visible through window 36. Asdose setting member 30 screws down distally, drive member 28 is advanceddistally to push piston 26 through reservoir 20 and expel medicationthrough needle 24 (FIG. 2 ).

During the dose dispensing operation, the amount of medicine expelledfrom the medication delivery device is proportional to the amount ofrotational movement of the dose setting member 30 relative to actuator50 as the dial member 32 screws back into housing 12. The injection iscompleted when the internal threading of dial member 32 has reached thedistal end of the corresponding outer threading of sleeve 34 (FIG. 2 ).Device 10 is then once again arranged in a ready state or zero doseposition as shown in FIGS. 2 and 3 .

The dose delivered may be derived based on the rotation of dose settingmember 30 relative to actuator 50 during dose delivery. This rotationmay be determined by detecting the incremental movements of the dosesetting member which are “counted” as the dose setting member is rotatedduring dose delivery.

Further details of the design and operation of an exemplary deliverydevice 10 may be found in U.S. Pat. No. 7,291,132, entitled MedicationDispensing Apparatus with Triple Screw Threads for Mechanical Advantage,the entire disclosure of which is hereby incorporated by referenceherein.

The dose detection systems use a sensing component and a sensedcomponent attached to members of the medication delivery device. Theterm “attached” encompasses any manner of securing the position of acomponent to another component or to a member of the medication deliverydevice such that they are operable as described herein. For example, asensing component may be attached to a member of the medication deliverydevice by being directly positioned on, received within, integral with,or otherwise connected to, the member. Connections may include, forexample, connections formed by frictional engagement, splines, a snap orpress fit, sonic welding or adhesive.

The term “directly attached” is used to describe an attachment in whichtwo components, or a component and a member, are physically securedtogether with no intermediate member, other than attachment components.An attachment component may comprise a fastener, adapter or other partof a fastening system, such as a compressible membrane interposedbetween the two components to facilitate the attachment. A “directattachment” is distinguished from an attachment where thecomponents/members are coupled by one or more intermediate functionalmembers, such as the way dose dial member 32 is coupled in FIG. 2 todose button 56 by clutch 52.

The term “fixed” is used to denote that an indicated movement either canor cannot occur. For example, a first member is “fixed rotationally”with a second member if the two members are required to move together inrotation. In one aspect, a member may be “fixed” relative to anothermember functionally, rather than structurally. For example, a member maybe pressed against another member such that the frictional engagementbetween the two members fixes them together rotationally, while the twomembers may not be fixed together absent the pressing of the firstmember.

Various sensor systems are contemplated herein. In general, the sensorsystems comprise a sensing component and a sensed component. The term“sensing component” refers to any component which is able to detect therelative position or movement of the sensed component. The sensingcomponent includes a sensing element, or “sensor”, along with associatedelectrical components to operate the sensing element. The “sensedcomponent” is any component for which the sensing component is able todetect the position and/or movement of the sensed component relative tothe sensing component. For the dose detection system, the sensedcomponent rotates relative to the sensing component, which is able todetect the rotational movement of the sensed component. The sensingcomponent may comprise one or more sensing elements, and the sensedcomponent may comprise one or more sensed elements.

The sensor system produces outputs representative of the movement of thesensed component. A controller is operably connected to the sensor toreceive the outputs. The controller is configured to determine from theoutputs the amount of dose delivered by operation of the medicationdelivery device.

Illustratively, the dose detection system includes an electronicsassembly suitable for operation of the sensor system as describedherein. A controller is operably connected to the sensor system toreceive outputs from the rotation sensor. The controller is configuredto determine from the outputs the amount of dose delivered by operationof the medication delivery device. The controller may includeconventional components such as a processor, power supply, memory,microcontrollers, etc. Alternatively, at least some components may beprovided separately, such as by means of a computer, smart phone orother device. Means are then provided to operably connect the externalcontroller components with the sensor system at appropriate times, suchas by a wired or wireless connection.

An exemplary electronics assembly 76 comprises a flexible printedcircuit board (FPCB) having a plurality of electronic components. Theelectronics assembly comprises a sensor system including one or moresensors operatively communicating with a processor for receiving signalsfrom the sensor representative of the sensed rotation. Electronicsassembly 76 further includes a microcontroller unit (MCU) comprising atleast one processing core and internal memory. The system includes abattery, illustratively a coin cell battery, for powering thecomponents. The MCU includes control logic operative to perform theoperations described herein, including determining a dose delivered bymedication delivery device 10 based on a detected rotation of the dosesetting member relative to the actuator. Many of the components of theelectronics assembly may be contained in a compartment 78 locatedproximal of the dose button 56.

The MCU is operative to store the detected dose delivery in local memory(e.g., internal flash memory or on-board EEPROM). The MCU is furtheroperative to wirelessly transmit a signal representative of the detecteddose to a paired remote electronic device, such as a user's smartphone.Transmission may, for example, be over a Bluetooth low energy (BLE) orother suitable short or long range wireless communication protocol.Illustratively, the BLE control logic and MCU are integrated on the samecircuit.

Disclosed herein is a medication delivery device including a dosedetection system operable to determine the amount of dose deliveredbased on relative rotation between a dose setting member and the devicebody. The dose detection system utilizes a dose setting member attachedto the device body and rotatable relative to the device body about anaxis of rotation during dose delivery. A sensed element is attached toand rotationally fixed with the dose setting member. An actuator isattached to the device body and is held against rotation relative to thedevice body during dose delivery. The sensed element thereby rotatesrelative to the actuator during dose delivery in relation to the amountof dose delivered.

The dose detection system involves detecting relative rotationalmovement between two members. With the extent of rotation having a knownrelationship to the amount of a delivered dose, the sensor systemoperates to detect the amount of angular movement from the start of adose injection to the end of the dose injection. For example, a typicalrelationship for a pen injector is that an angular displacement of adose setting member of 18° is the equivalent of one unit of dose,although other angular relationships are also suitable. The sensorsystem is operable to determine the total angular displacement of a dosesetting member during dose delivery. Thus, if the angular displacementis 90°, then 5 units of dose have been delivered.

The angular displacement is determined by counting increments of doseamounts as the injection proceeds. For example, a sensing system may usea repeating pattern of a sensed element, such that each repetition is anindication of a predetermined degree of angular rotation. Conveniently,the pattern may be established such that each repetition corresponds tothe minimum increment of dose that can be set with the medicationdelivery device.

The sensor system components may be permanently or removably attached tothe medication delivery device. In an illustrative embodiment, as leastsome of the dose detection system components are provided in the form ofa module that is removably attached to the medication delivery device.This has the advantage of making these sensor components available foruse on more than one pen injector.

The sensor system detects during dose delivery the relative rotation ofthe sensed component, and therefore of the dose setting member, fromwhich is determined the amount of a dose delivered by the medicationdelivery device. In an illustrative embodiment, a rotation sensor isattached, and rotationally fixed, to the actuator. The actuator does notrotate relative to the body of the medication delivery device duringdose delivery. In this embodiment, a sensed component is attached, androtationally fixed, to the dose setting member, which rotates relativeto the actuator and the device body during dose delivery.

In one aspect, there is provided a dose detection system in the form ofa module useful in combination with a medication delivery device. Themodule may carry various components of a sensor system, which thereforemay be moved from one delivery device to another. The module inparticular comprises a rotation sensor and other associated componentssuch as a processor, memory, battery, etc. The module may be provided asa component which is removably attachable to the dose setting member,the actuator, or potentially other parts of the medication deliverydevice.

Illustratively, the dose detection module includes a body attached todose button 56 and includes a cylindrical side wall and a top wallspanning over and sealing the side wall. By way of example, the modulemay include inwardly-extending tabs attaching the module to the annularlip 64 of dose button 56. In another approach, distal pressing of themodule provides a sufficient frictional engagement between the moduleand dose button 56 as to functionally cause the module and dose button56 to remain rotationally fixed together during dose delivery. However,attached, the module is rotationally fixed with the actuator so as notto rotate relative to the actuator during dose delivery. The module isprovided such that pressing on the module delivers a set dose.

The dose detection system comprises a module including a rotation sensorattached to the actuator. The sensed element is rotationally fixed withthe dose setting member and includes alternating, first and secondsurface features radially-spaced about the axis of rotation of the dosesetting member. The rotation sensor includes a light source for emittingsensing light in a sensing direction during dose delivery. The rotationsensor further includes a light sensor positioned to receive the sensinglight emitted in the sensing direction.

Rotation of the sensed element during dose delivery positions the firstand second surface features in the path of the sensing light. The firstsurface features result in the sensing light being detected by the lightsensor, the second surface features result in the sensing light notbeing detected by the light sensor. In one aspect, the first and secondsurface features may be uniformly configured and spaced intermittentlyaround the axis of rotation of the sensed element. In a particularaspect, the surface features are equi-radially spaced about the axis ofrotation.

In one embodiment, the first and second surface features comprise openand closed portions which operate to either allow the sensing light topass through the open portions and ultimately to the light sensor, or toblock the sensing light from passing through the closed portions to thelight sensor. In this embodiment, the open and closed portions may bedefined by apertures formed in a continuous surface, and in anotheraspect the open and closed portions may be defined by castellation'sformed by alternating projections and recesses. In another embodiment,the first and second features may comprise surfaces which are reflectiveand non-reflective, respectively. The light emitted in the sensingdirection is then either reflected or not reflected to the light sensorduring rotation of the sensed element relative to the actuator duringdose delivery.

The rotation sensor is responsive to the detection of the sensing lightto detect rotation of the dose setting member relative to the actuatorduring dose delivery. The module may further comprise an electronicsassembly including a controller responsive to the rotation sensor todetermine the amount of dose delivery based on the detected rotation ofthe dose setting member relative to the actuator during dose delivery.

The sensing direction may be any that is detectable by the light sensor.For example, the sensing direction may be in a radial direction,orthogonal to the axis of rotation of the sensed element. Thus, the openportions may be provided as apertures in a cylindrical wall.Alternatively, the open portions may be formed by castellation's formedby axially directed projections extending proximally or distally from asupport surface. As another example, the sensing direction may be in anaxial direction, parallel to the axis of rotation of the sensed element.Thus, the open portions may be provided as apertures in a circular orannular wall. Alternatively, the open portions may be formed bycastellation's formed by spaced, radially-directed projections extendinginwardly or outwardly.

The sensed element is attached to or may be formed integrally with thedose setting member. Depending on the medication delivery device, thesensed element may be attached to the skirt, the flange or the dosedial, or any other component that rotates relative to the actuator andthe device body during dose delivery in relation to the amount of dosedelivered.

Referring to FIG. 5 , there is shown in diagrammatic form a dosedelivery detection system 80 including a module 82 useful in combinationwith a medication delivery device, such as device 10. Module 82 carriesa sensor system, shown generally at 84, including a rotation sensor 86and other associated components such as a processor, memory, battery,etc. Module 82 is optionally provided as a separate component which maybe removably attached to actuator 50.

Dose detection module 82 includes a body 88 attached to dose button 56.Body 88 illustratively includes a cylindrical side wall 90 and a topwall 92, spanning over and sealing side wall 90. Body 88 furtherincludes an attachment, such as shown at 94, attaching module 82 to dosebutton 56 such that pressing on the module delivers a set dose. Dosedetection module 82 may be attached to dose button 56 via any suitablefastening means, such as a snap or press fit, threaded interface, etc.,provided that in one aspect module 82 may be removed from a firstmedication delivery device and thereafter attached to a secondmedication delivery device. The attachment may be at any location ondose button 56, provided that dose button 56 is able to move anyrequired amount axially relative to dose setting member 30, as discussedherein.

During dose delivery, dose setting member 30 is free to rotate relativeto dose button 56 and module 82. In the illustrative embodiment, module82 is rotationally fixed with dose button 56 and does not rotate duringdose delivery. In another embodiment, the distal pressing of the moduleprovides a sufficient frictional engagement between module 82 and dosebutton 56 as to functionally cause the module 82 and dose button 56 toremain rotationally fixed together during dose delivery.

Top wall 92 is spaced apart from proximal face 60 of dose button 56 andthereby provides a compartment 78 containing some or all of electronicsassembly 76. Compartment 78 defines a chamber 96 and may be open at thebottom, or may be enclosed, such as by a bottom wall.

In FIG. 6 there is shown an example of a sensed element 98 includingalternating open portions 100 and closed portions 102. In the embodimentof FIG. 6 , the open and closed portions are formed by castellation's,in which the open portions are formed by recesses 104 between spacedprojections 106. Projections 106 extend axially in the proximaldirection. It will be appreciated, however, that the open portions mayinstead comprise apertures in an otherwise solid wall. The open andclosed portions are shown as being formed in a proximal extension ofdose dial 32, but it will be appreciated that they may also be formed inother dose setting members, such as flange 38 or skirt 42.

Referring to FIGS. 7 and 8 , there are shown two different positions formodule body 88 relative to device housing 12. In FIG. 7 , the module isin a first operating mode in which the module may be used to set a dose.In certain embodiments, the module and dose button are rotationallyfixed to the dose setting member in this mode, and module body 88 may berotated to set a dose. In this position, projections 106 are axiallydisplaced from the light source 108 and the light sensor 110. Inaddition, wake-up switch 112 is displaced from contact 114 defined bythe axial proximal end of flange 38. Triggering of wake-up switch 112 isconfigured to allow power transmission from the power source (orbattery) for powering up the electronic components for dose sensing inorder to minimize inadvertent power loss or usage when a dose dispensingevent is not occurring. As shown, wake-up switch 112 may be locatedalong the bottom side or distally facing end 115′ of an intermediatebody wall 115 of module 82 that at least partially transverses anintermediate portion of chamber 96 cavity defined by body 88 of module82. As shown, contact 114 may be located radially inward from housing ofdose dial 32 and in a more distal location relative to an axial proximalend 32′ of the wall of dose dial 32. Wake-up switch 112 is showndisposed radially between external part of spring 68 and the interiorluminal surface of dose dial 32. Due to the tight area in which thecomponents are packaged, it may be beneficial to position wake-up switch112 circumferentially offset from light source 108 and sensor 110, suchas for example, about 180 degrees from one another.

Upon pressing top wall 92 of module 82, dose button 56 advances distallyrelative to housing 12, compressing spring 68. Wake-up switch 112 istriggered by being pressed against contact 114, and the electronicsassembly is activated. In order to prevent over depression of the buttonthat could lead to component damage, the axial extent of travel of dosebutton/module combination may be limited. For example, axial proximalend 32′ of the wall of dose dial 32 may define a physical stop that inis in a contacting relationship with distally facing end 115′ ofintermediate body wall 115 of module 82. Such physical stop may also aidin alignment of said sensing components for more accurate and consistentreadings. At the same time, rotation sensor 86 is advanced such thatprojections 106 are received between light source 108 and light sensor110 (FIG. 8 ). Continued pressing of the module distally results in backdriving dose dial 32 in a spiral direction relative to housing 12. FIG.8 shows the medication delivery device with module 82, and thereforedose button 56, still depressed but with dose dial 32 having been drivenback to the zero dose position relative to housing 12.

In the embodiment of FIGS. 5-8 , light source 108 and light sensor 110are shown attached to a printed circuit board (“PCB”) 116 attached toactuator 50. In this configuration, light source 108 is positioned toemit sensing light in a radially-outward sensing direction. Light sensor110 is positioned in alignment with light source 108 to directly receivethe sensing light. As sensed element 98 rotates, recesses 104 andprojections 106 will successively be positioned in line with the sensinglight being emitted in the sensing direction.

In an alternate embodiment, light sensor 110 is positioned to receivereflected light rather than direct light. Referring to FIG. 9 , there isshown diagrammatically a dose detection system similarly usingalternating open and closed portions of the dose setting member. Thisembodiment is comparable to the embodiment of FIGS. 5-8 , except for thepositioning of the light source and light sensor. In FIG. 9 , lightsource 108 and light sensor 110 are positioned interior of a cylindricalwall 118 including an opening 120. Side wall 90 of module 82 includes areflective surface 122 aligned with opening 120. Light source 108 isdirected outwardly at a slight angle from radially to emit sensing lightthrough opening 120 in wall 118. Light emitted in this direction andpassing through open portions 100 in sensed element 98 is reflected backthrough opening 120 and is received by light sensor 110.

In either approach, light receptor 110 operates to detect when thesensing light is and is not received by light sensor 110 and rotationsensor 86 is thereby able to detect rotation of dose setting member 30relative to actuator 50 during dose delivery.

Referring to FIG. 10 , medication delivery device 10 includes a module200 having a housing assembly 201 comprising a coupling component 202and a dosing component 203. Coupling component 202 includes a firsthousing portion 204. Dosing component 203 includes a second housingportion 206 coupled to first housing portion 204. As described herein,first and second housing portions 204, 206 are rotatable relative toeach other about a longitudinal axis and are axially movable relative toeach other along the axis. First housing portion 204 includes a couplingwall 208, illustratively in the form of a cylinder, and a couplingmember 210 fixed to a distal end of coupling wall 208. Coupling wall 208and coupling member 210 may be fixed together via any suitable fasteningmeans, such as a weld, snap fit, threaded interface, etc., oralternatively may be integrally formed as a single component. In anillustrative embodiment, coupling member 210 includes an annular ridge212 that extends axially from the proximal end forming an annularshoulder 214 between ridge 212 and an outer surface 216 of couplingmember 210. The distal end of coupling wall 208 includes projection 217which snap fits onto coupling member 210 to rotationally and axially fixcoupling member 210 to coupling wall 208. When coupled together, thedistal end of coupling wall 208 abuts annular shoulder 214 of couplingmember 210.

Coupling member 210 includes an annular ring portion 218 sized toreceive skirt 42 and to engage the outer surface of skirt 42 forattaching first housing portion 204 to delivery device 10. Asillustrated, outer surface 216 of coupling member 210 tapers radiallyinwardly from shoulder 214 to ring portion 220 such that a proximal enddiameter of coupling member 210 is larger than a distal end diameter ofcoupling member 210. An inner surface 222 of ring portion 220 includes aplurality of contour features 224, illustratively variably sizedprojections and grooves, that are sized to engage corresponding surfacecontours 48 (e.g., grooves) of skirt 42 for coupling thereto. In theillustrated embodiment, surface contours 48 of coupling member 210couple to annular ridge 49 of skirt 42 via a snap fit or an interferencefit, although any other suitable fastening mechanism may alternativelybe used to couple first housing portion 204 to skirt 42.

In the illustrative embodiment, contour features 224 and surfacecontours 48 are sized, shaped, and spaced to provide mechanical keyingof housing assembly 201 to delivery device 10. In particular, in theillustrative embodiment, housing assembly 201 is mechanically keyed viacontour features 224 to be compatible with a specific type or types ofdelivery devices having compatible surface contours 48, such as based onmedication type, concentration, strength, volume, and/or formulation, aswell as cartridge size or other aspects of the corresponding deliverydevice. In some embodiments, electronics assembly 76 of module 200 ispre-programmed to operate based on the compatible delivery device(s)and/or medication. Such mechanical keying serves to reduce thelikelihood that detection module 200 is used with an incorrect deliverydevice and/or medication.

With the mechanical key feature, module 200 must be in proper rotationalalignment with skirt 42 of device 10 to slide and snap coupling member210 onto skirt 42. Coupling member 210 illustratively may be providedwith a projection or other visual reference on its outer surface 216that serves as a guide for rotationally aligning module 200 to skirt 42.Other keying features, such as color coding, may be used to identify acorrect module 200 for a corresponding medication delivery device 10.

Second housing portion 206 includes a drum 226 and a cap portion 228coupled to a proximal end of drum 226. Drum 226 illustratively includesinner wall 230 and a disc-shaped base wall 232 at a distal end of innerwall 230. Cap portion 228 includes an end wall 234 positionedorthogonally to inner wall 230. End wall 234 illustratively includes adistal wall portion 236 and a proximal wall portion 238 coupled todistal wall portion 236 at a centrally located mounting interface 240via a snap fit, interference fit, ultrasonic weld, or other suitablecoupling mechanism. Cap portion 228 further includes an outer wall 242radially spaced apart from and substantially parallel to inner wall 230.In the illustrated embodiment, coupling wall 208 of first housingportion 204 is positioned in the gap formed radially between outer wall242 and inner wall 230 of second housing portion 206. End wall 234 ofcap portion 228 includes a mounting collar 244 axially extending fromand centrally located on distal wall portion 236. Upper wall portion 246of inner wall 230 is fixed to mounting collar 244 via any suitablecoupling mechanism, such as ultrasonic weld or interference fit forexample.

When module 200 is attached to delivery device 10, a distal surface ofbase wall 232 abuts the proximal end surface of dose button 56.Illustratively, the distal surface of base wall 232 includes a thin,disc-shaped friction pad 248 having a central opening. Pad 248 providesfrictional resistance (e.g., via surface roughness and/or adhesive)between base wall 232 and dose button 56 such that second housingportion 206 remains rotationally coupled to dose button 56 during adosing operation of module 200 with device 10. Base wall 232 of drum 226in some embodiments may include a centrally located, axially extendingprojection (not shown) configured for receipt within a recessed portionof dose button 56, such as for coupling and/or alignment of dose button56 and base wall 232.

In the illustrated embodiment, when dose detection module 200 isattached to delivery device 10, first and second housing portions 204,206 and skirt 42 are coaxial and are thus operative to rotate togetherabout a same longitudinal axis during a dose setting operation ofdelivery device 10. In addition, first and second housing portions 204,206 are operative to move axially together with skirt 42 along thelongitudinal axis during the dose setting operation and axially relativeto each other along the longitudinal axis in response to an axial forceon second housing portion 206 to start the dose delivery operation.While coupling wall 208 and inner wall 230 of respective first andsecond housing portions 204, 206 illustratively extend 360 degrees aboutthe longitudinal axis of module 200, walls 208, 230 alternatively mayextend a portion of the full circumference about the axis. In otherwords, circumferential walls 208, 230 may include one or more breaks inthe respective wall somewhere along the perimeter rather than beingcontinuous walls as illustrated.

Dose detection module 200 is configured for operation in at least afirst operating mode and a second operating mode. In the illustratedembodiment, the first operating mode corresponds to the dose settingoperation of delivery device 10, and the second operating modecorresponds to the dose dispensing operation of delivery device 10. Inthe first operating mode, shown in FIG. 10 , first and second housingportions 204, 206 are at a home position axially wherein second housingportion 206 is not axially compressed relative to first housing portion204. In this first operating mode, first and second housing portions204, 206 are rotationally locked together by a locking mechanism,illustratively a tooth and slot coupling.

The proximal end of coupling wall 208 of first housing portion 204includes a radially extending annular lip 250 having a plurality ofcircumferentially spaced slots 252 formed therein. Slots 252 are eachsized to receive a tooth or tongue 254 formed on the outer surface ofupper wall portion 246 of inner wall 230. Illustratively, four teeth arespaced 90 degrees apart around upper wall portion 246, and twenty slots252 are equally spaced around lip 250, although any suitable number ofteeth and slots may be provided. In the illustrative embodiment, thenumber of slots 252 is the same as the number of rotational incrementsor clicks to which dose setting member 30 of device 10 may be set in onecomplete rotation of dose dial member 32 relative to housing 12. Themultiple slots allow first housing portion 204 and second housingportion 206 to lock together in the first operating mode in multiplerelative rotational positions, with more slots providing more possiblerelative positions. In an alternative embodiment, slots 252 may beformed on inner wall 230 and teeth formed on coupling wall 208. Othersuitable rotational locking mechanisms may be provided.

In general, dosing component 202 in the first operating mode during dosesetting is axially and rotationally fixed to coupling component 202. Inthis first mode, dosing component 203 may be grasped by the user androtated relative to device body 11. Due to the connections betweendosing component 203 and coupling component 202, and between couplingcomponent 202 and dose setting member 30, the rotation of dosingcomponent 203 results in rotation of dose setting member 30 and a doseis set. During dose setting, actuator 50, including dose button 56, isconnected by way of clutch 44 to dose setting member 30 and spirals withdose setting member 30 relative to device body 11.

In one embodiment, dosing component 203 includes inner wall 230 andouter wall 242, and coupling component 202 includes coupling wall 208received between the inner and outer walls. Dose setting member 30includes an exposed circumferential surface 256, optionally includingsurface contours 48, for use in rotating dose setting member 30 relativeto device body 11. Coupling wall 208 extends distally beyond inner wall230 and includes a coupling portion 258 attached to exposedcircumferential surface 256 of dose setting member 30 in order to attachcoupling component 202 to dose setting member 30. In another aspect, asshown at 260, outer wall 242 extends distally to radially overlap someor all of the exposed circumferential surface 256 of the dose settingmember and/or the coupling member 210.

Dosing component 203 is rotationally locked with coupling component 202during dose setting. As previously indicated, this may be accomplishedby way of a variety of locking mechanisms. Illustratively, coupling wall208 is received in the gap between inner wall 230 and outer wall 242. Asdescribed, the locking mechanism may comprise mechanical features, suchas teeth received within slots, or complementary shaped, mutually-facingteeth extending axially from the coupling and dosing components. Theteeth in either event may, for example, be formed on coupling wall 208of coupling component 202 and on one of the inner and outer walls 230,242 of dosing component 203. In a further aspect, to reduce the risk ofdamage to the medication delivery device, the locking mechanism isconfigured to cause disengagement of the dosing component from thecoupling component in the event that a rotational force is applied fromthe dosing component to the coupling component in excess of apredetermined amount.

Illustratively, the locking mechanism is configured also to allow fordisengagement upon axial movement of dosing component 203 towardcoupling component 202. Once disengaged, coupling component 202 is freeto rotate relative to dosing component 203. Axial movement of actuator50 in the direction of dose setting member 30 results in clutch 52disconnecting the rotational engagement of actuator 50 with dose settingmember 30. In one aspect, pressing housing assembly 201 moves dosingcomponent 203 closer to coupling component 202 and coupling component202 is thereby rotationally disengaged from dosing component 203. Thisoccurs before actuator 50 moves a sufficient distance to initiate dosedelivery. In another aspect, a wake-up switch, such as described above,is provided to cause relevant components of electronics assembly 76 toactivate in time to detect the dose delivery. In another aspect,pressing housing assembly 201 disengages dosing component 203 fromcoupling component 202 and engages the wake-up switch, and subsequentdistal movement presses dose button 56 sufficiently to cause dosedelivery. Although not shown, such wake-up switch may be positionedwithin cavity defined by wall portion 62 of dose button 56 andconfigured to contact the dose dial 32 or flange 38 when in the secondmode. In other embodiments, the wake-up switch may be otherconfigurations, such as electrical contacts or accelerometer and may bepositioned within the module body.

Although not required, the disengagement of dosing component 203 fromcoupling component 202 may occur such that there is no contact betweenthose two components once disengaged. For example, the upper end 262 ofcoupling wall 208 may be spaced apart from mounting collar 244 and theinterior 264 of distal wall portion 236. Providing such a space avoidscontact between coupling wall 208 and outer wall 242, which couldotherwise provide frictional resistance to rotation of couplingcomponent 202 relative to dosing component 203 during dose delivery.

In the second operating mode of module 200, the locking mechanism isdisengaged, and first and second housing portions 204, 206 are rotatablerelative to each other. An axial movement or compression of secondhousing portion 206 relative to first housing portion 204 is operativeto transition module 200 from the first operating mode to the secondoperating mode by disengaging the locking mechanism to allow relativerotation of first and second housing portions 204, 206 about thelongitudinal axis of module 200. In particular, the axial movement ofsecond housing portion 206 towards first housing portion 204 causesteeth 254 to axially slide out of corresponding slots 252 torotationally uncouple first and second housing portions 204, 206.

In general, in the second operating mode during dose delivery, couplingcomponent 202 is rotatable relative to dosing component 203. In thissecond mode, dosing component 203 is axially and rotationally fixed toactuator 50. Dosing component 203 is axially fixed in that the dosingcomponent bears against actuator 50 as housing assembly 201 is presseddistally to deliver a dose. Further, dosing component 203 isrotationally fixed to actuator 50 either by a frictional engagement orby other locking means as previously described. During dose delivery,actuator 50, including dose button 56, is pressed by the user andtranslates axially, while being held from rotating relative to devicebody 11. Since clutch 52 has released the rotational connection betweenactuator 50 and dose setting member 30, the dose setting member spiralsback into device body 11.

In the first operating mode with module 200 coupled to delivery device10, a rotational or screw force on module 200, such as applied to outerwall 242 or any other user accessible portion, causes correspondingrotation and axial motion of dose setting member 30 to operatemedication delivery device 10 in the dose setting mode described herein.In the second operating mode with module 200 coupled to delivery device10, the axial force which compresses module 200 is transferred to dosebutton 56 and thereby rotationally disengages actuator 50 from dosesetting member 30, causing dose setting member 30 to screw back intohousing 12 to operate device 10 in the dose delivery mode. During thedose delivery operation of device 10, first housing portion 204 screws(moves axially and rotationally) with dose setting member 30 whilesecond housing portion 206 remains rotationally fixed while moving onlyaxially with dose setting member 30. In an exemplary mode of use forattachment of module 200 to device 10, the user aligns the visualalignment feature(s) of module 200 and device 10, and module 200 is snapfitted to dose setting member 30 of device 10. The locking mechanism(e.g., teeth 254 and slots 256) ensures proper alignment of therotational sensor.

In an exemplary mode of use for dialing a dose, dosing component 203 ofmodule 200 is rotated relative to housing 12 of device 10, and suchrotation is translated to dose setting member 30 to screw dose dialmember 32 up to the desired dose amount. In an exemplary mode of use forinjecting a dose, cap portion 228 of module 200 is axially pushedrelative to housing 12 to start an injection. The axial force disengagesthe locking mechanism in module 200 and the clutch 52 in delivery device10, and first housing portion 204 is free to rotate relative to secondhousing portion 206 and dose dial member 32 is free to rotate relativeto dose button 56 of device 10.

When injection ends, the user releases cap portion 228, and electronicassembly 76 captures the injection event until a certain timeout period,stores the dose information, and starts activity in order toautomatically update the app running in the remote smartphone. In caseof a transmission failure, manual sync of module 200 with the smartphoneis possible later to transmit the dose information. Followingtransmission, module 20 transitions again to deep sleep state (low powermode). In an exemplary mode of use for detaching module 200 from device10, module 200 is detached by pulling module 200 with the required forceaway from device 10.

Further details of the design and operation of an exemplary medicationdelivery device may be found in U.S. Pat. No. 7,291,132, entitledMedication Dispensing Apparatus with Triple Screw Threads for MechanicalAdvantage, the entire disclosure of which is hereby incorporated byreference herein.

In reference to FIGS. 10-12 , an alternate embodiment for the dosedetection system is shown in combination with a medication deliverydevice 10. Dose detection system 300 includes housing assembly 201including coupling component 202 and dosing component 203. Module 200carries a sensor system, shown generally at 302, including a rotationsensor 304 and a sensed element 306. As before, module 200 may beprovided as a separate component which may be removably attached to theactuator, or the components of module 200 may be integrated into themedication delivery device.

Rotation sensor 304 is shown attached to inner wall 230 and comprisestwo components, a light source 308 and a light sensor 310. Both lightsource 308 and light sensor 310 are operatively connected to electronicassembly 76. For example, light source 308 and light sensor 310 may beattached to a printed circuit board (“PCB”) forming a part ofelectronics assembly 76. Rotation sensor 304 operates in conjunctionwith sensed element 306 which is shown attached through coupling wall208 and coupling member 210 to dose setting member 30, for example skirt42. Illustratively, sensed element 306 is attached to or is integralwith coupling wall 208. Although shown as separate elements, couplingmember 210 may be formed integral with coupling wall 208.

Sensed element 306 in general has an annular shape 311 and is attachedto the interior of coupling wall 208. Sensed element 306 includesalternating open portions 312 and closed portions 314. In the embodimentof FIG. 12 , the open and closed portions are formed by castellation's,in which the open portions are formed by recesses 316 between spacedprojections 318. Projections 318 extend radially-inward. It will beappreciated that the open portions 312 may instead comprise apertures320 in an otherwise solid sensed element 306. Alternatively, sensedelement 306 may be formed integral with coupling wall 208. For example,sensed element 306 may be formed as spaced projections attached to orintegral with coupling wall 208 and extending radially inward. The openand closed portions are shown as being attached through coupling wall208 and coupling member 210 to skirt 42. However, coupling wall 208 mayalso be attached to any other component of dose setting member 30,including for example dose dial 32 or flange 38.

Referring to FIGS. 11-12 , further details of dose detection system 300are shown. Light source 308 and light sensor 310 are positioned in FIG.11 such that light is emitted by light source 308 in an axial, distaldirection. As shown, the light source 308 and light sensor 310 radiallyoverlap with projection 318. In this design, the spacing of projections318 may be such as to allow assembly of the module, for example bypassage of light source 308 and/or light sensor 310 between projections318. This may be further facilitated by a keyed connection providingalignment of first housing portion 204 with second housing portion 206.The embodiment of FIG. 11 may alternatively be configured such thatradially overlapping does not exist in the assembled module.

Rotation of sensed element 306 relative to rotation sensor 304 occursduring dose delivery. The open and closed portions of sensed element 306are positioned to intermittently prevent light from light source 308being received by light sensor 310. These intermittent conditions aredetected and used to determine rotation of dose setting member 30relative to actuator 50 during dose delivery, and the amount of dosedelivered is derived therefrom.

Dosing component 203 is shown in FIG. 10 in the at-rest position with adose not having been set, as shown by the fact that dose dial 32 andskirt 42 are adjacent device housing 12. In setting a dose, the entirehousing assembly 201 will translate and rotate away from device housing12. In order to deliver the dose, dosing component 203 is pressed in thedirection of coupling component 202 and is axially displaced closer tocoupling component 202. To accommodate this relative axial movement,light source 308 and light sensor 310 are axially spaced sufficiently toallow the axial movement of sensed element 306.

In the method of using dose detection system 300, the dose is set by useof module 200, and particularly outer wall 242. Dose delivery isinitiated by pressing module 200 distally and causing back driving ofdose setting member 30 in a spiral direction relative to housing 12.Light source 308 is positioned to emit sensing light in an axial sensingdirection. Light sensor 310 is positioned in alignment with light source308 to directly receive the sensing light. As sensed element 306rotates, recesses 316 and projections 318 will successively bepositioned in line with the sensing light being emitted in the sensingdirection.

In an alternate embodiment, light sensor 310 is positioned to receivereflected light rather than direct light. Referring to FIG. 13 , thereis shown diagrammatically a dose detection system similarly usingalternating open and closed portions of the dose setting member 30. Thisembodiment is comparable to the embodiment of FIG. 12 , except for thepositioning of light source 308 and light sensor 310. Light source 308emits light at a slight angle to axial. As a projection 318 passes infront of the light, the sensing light is reflected back off of theprojection and impinges on the light sensor 310.

There have thus been described illustrative embodiments of a medicationdelivery device including a module providing components useful to detectthe amount of a delivered dose. The medication delivery device includesa device body and a dose setting member attached to the device body androtatable relative to the device body about an axis of rotation duringdose delivery. The device also includes a sensed element attached to androtationally fixed with the dose setting member, the sensed elementincluding alternating first and second surface features radially-spacedabout the axis of rotation of the dose setting member. An actuator isattached to the device body and is non-rotatable relative to the devicebody during dose delivery, and the sensed element rotates relative tothe actuator during dose delivery in relation to the amount of dosedelivered.

A module is axially and rotationally fixed with the actuator during dosedelivery. The module comprises a rotation sensor including a lightsource emitting sensing light in a sensing direction during dosedelivery. The rotation sensor further includes a light sensor positionedto receive the sensing light emitted in the sensing direction. Rotationof the sensed element during dose delivery positions the first andsecond surface features in the path of the sensing light. The firstsurface features result in the sensing light being detected by the lightsensor, and the second surface features result in the sensing light notbeing detected by the light sensor. The rotation sensor is responsive tothe detection of the sensing light to detect rotation of the dosesetting member relative to the actuator during dose delivery. The modulefurther comprises an electronics assembly responsive to the rotationsensor to determine the amount of dose delivery based on the detectedrotation of the dose setting member relative to the actuator during dosedelivery.

Illustratively in one embodiment, the module has a first operating modeand a second operating mode relative to said actuator. The module in thefirst operating mode during dose setting is directly attached to theactuator and is axially and rotationally fixed to the dose settingmember. The module in the second operating mode is axially androtationally fixed to the actuator and is rotatable relative to the dosesetting member during dose delivery. The module optionally moves axiallydistally from the first operating mode to the second operating mode.

In an alternate embodiment, the dose detection system includes acoupling component which is attached directly to the dose settingmember. The dose detection system further includes a dosing componentwhich is axially and rotationally fixed to the actuator in a secondoperating mode during dose delivery. The coupling component and the dosesetting member are rotatable relative to the actuator and the dosingcomponent during dose delivery. In one aspect, the dosing componentmoves axially distally from the first operating mode to the secondoperating mode. In another aspect, the coupling component is axiallyfixed to the dosing component during dose setting, and is rotatablerelative to the dosing component during dose delivery. In an exemplaryform, the dose setting member includes an exposed circumferentialsurface for use in rotating the dose setting member relative to thedevice body for setting a dose, and the coupling component includes acoupling portion attached to the exposed circumferential surface of thedose setting member.

In one aspect, the dose detection system is originally incorporated intoa medication delivery device as an integrated system. In another aspect,there is disclosed a modular form of the dose detection system. The useof a removably attached module is particularly adapted to use with amedication delivery device in which the actuator and/or the dose settingmember include portions external to the device housing. These externalportions allow for direct attachment of the module to the actuator, suchas the dose button or skirt, and also attachment of the sensed elementto the dose setting member, such as a skirt, flange, or dose dialmember. Alternatively, the sensed element is integral with themedication delivery device and the module is removably attached. Thishas the advantage that the more complex and expensive electronics,including the rotation sensor and controller, may be reused withdifferent medication deliver devices. By comparison, the sensed elementmay use relatively simple features, for example radially-spacedprojections, which do not add significantly to the cost of themedication delivery device. Any of the devices described herein maycomprise any one or more of medications described herein, such as, forexample, within the cartridge of the device.

The invention claimed is:
 1. A medication delivery device comprising: adevice body; a dose setting member attached to said device body androtatable relative to said device body about an axis of rotation duringdose setting and during dose delivery; a sensed element attached to androtationally fixed with said dose setting member, said sensed elementincluding alternating first and second surface features radially-spacedabout the axis of rotation of said dose setting member; an actuatorattached to said device body, said actuator being axially androtationally fixed with said dose setting member in a first operatingmode during dose setting, said actuator being non-rotatable relative tosaid device body in a second operating mode during dose delivery, saidsensed element and said dose setting member rotating relative to saidactuator during dose delivery in relation to the amount of dosedelivered; and a rotation sensor attached to said actuator during dosedelivery, said rotation sensor including a light source emitting sensinglight in a sensing direction during dose delivery, said rotation sensorfurther including a light sensor positioned to receive the sensing lightemitted in the sensing direction during dose delivery, wherein thealternating first and second surface features are arranged to bereceived between the light source and the light sensor, and wherein inthe first operating mode the alternating first and second surfacefeatures are axially displaced from the light source and the lightsensor, and wherein the rotation sensor is movable distally relative tothe sensed element in the second operating mode such that thealternating first and second surface features are received between thelight source and the light sensor, rotation of said sensed elementduring dose delivery positioning the first and second surface featuresin the path of the sensing light, the first surface features resultingin the sensing light being detected by the light sensor, the secondsurface features resulting in the sensing light not being detected bythe light sensor, the rotation sensor being responsive to the detectionor non-detection of the sensing light to detect rotation of said dosesetting member relative to said actuator during dose delivery; and anelectronics assembly responsive to the rotation sensor to determine theamount of dose delivery based on the detected rotation of said dosesetting member relative to said actuator during dose delivery.
 2. Themedication delivery device of claim 1 in which the surface featurescomprise reflective and non-reflective surfaces.
 3. The medicationdelivery device of claim 1 in which the surface features comprisealternating open and closed portions of said sensed element.
 4. Themedication delivery device of claim 1 in which the surface featurescomprise alternating projections and recesses.
 5. The medicationdelivery device of claim 4 in which the projections extend axially. 6.The medication delivery device of claim 5 further including a lightreflective surface, the light sensor being positioned to receive lightemitted by the light source and reflected by the light reflectingsurface.
 7. The medication delivery device of claim 5 in which said dosesetting member is a skirt.
 8. The medication delivery device of claim 1in which said dose setting member is a dose dial.
 9. The medicationdelivery device of claim 1 comprising a reservoir disposed within thedevice body, the reservoir including a medication.
 10. A medicationdelivery device comprising: a device body; a dose setting memberattached to said device body and rotatable relative to said device bodyabout an axis of rotation during dose setting and during dose delivery;a sensed element rotationally fixed with said dose setting member, saidsensed element including alternating first and second surface featuresradially-spaced about the axis of rotation of said dose setting member;an actuator attached to said device body, said actuator being axiallyand rotationally fixed with said dose setting member in a firstoperating mode during dose setting, said actuator being non-rotatablerelative to said device body in a second operating mode during dosedelivery, said sensed element and said dose setting member rotatingrelative to said actuator during dose delivery in relation to the amountof dose delivered; and a rotation sensor attached to said actuatorduring dose delivery, said rotation sensor including a light sourceemitting sensing light in a sensing direction during dose delivery, saidrotation sensor further including a light sensor positioned to receivethe sensing light emitted in the sensing direction during dose delivery,rotation of said sensed element during dose delivery positioning thefirst and second surface features in the path of the sensing light, thefirst surface features resulting in the sensing light being detected bythe light sensor, the second surface features resulting in the sensinglight not being detected by the light sensor, the rotation sensor beingresponsive to the detection or non-detection of the sensing light todetect rotation of said dose setting member relative to said actuatorduring dose delivery; and an electronics assembly responsive to therotation sensor to determine the amount of dose delivery based on thedetected rotation of said dose setting member relative to said actuatorduring dose delivery, which comprises a module removably attached tosaid device body, the module comprising a coupling component attacheddirectly to said dose setting member and a dosing component, thecoupling component comprising the sensed element and the dosingcomponent comprising the rotation sensor and said electronics assembly,wherein the dosing component includes an inner wall and an outer wall,the rotation sensor is attached to the inner wall, wherein the sensedelement is attached to an interior of a coupling wall of the couplingcomponent, the coupling wall is received between the inner wall and theouter wall.
 11. The medication delivery device of claim 10 in which theprojections extend radially outward.
 12. The medication delivery deviceof claim 11 in which the light sensor is positioned to directly receivelight emitted by the light source.
 13. The medication delivery device ofclaim 10 in which said module is attached directly to said actuator. 14.The medication delivery device of claim 13 in which said module is notdirectly attached to said dose setting member during dose setting orduring dose delivery.
 15. The medication delivery device of claim 10 inwhich said module moves axially distally from the first operating modeto the second operating mode, wherein the module comprises a wake-upswitch that activates upon contact with said dose setting member whenthe module is in the second operating mode.
 16. The medication deliverydevice of claim 10 in which said dosing component in the secondoperating mode is axially and rotationally fixed to said actuator. 17.The medication delivery device of claim 16 in which the dosing componentis not directly attached to said actuator during dose setting.
 18. Themedication delivery device of claim 16 in which the dosing component isrotationally locked with the coupling component during dose setting. 19.The medication delivery device of claim 18 in which said module movesaxially distally from the first operating mode to the second operatingmode, in which movement of said module from the first operating mode tothe second operating mode unlocks the rotational fixing of the dosingcomponents with the coupling component.
 20. The medication deliverydevice of claim 16 in which said dose setting member includes an exposedcircumferential surface for use in rotating said dose setting memberrelative to said device body, the coupling component extending distallybeyond the inner wall and including a coupling portion attached to theexposed circumferential surface of said dose setting member.
 21. Themedication delivery device of claim 10, wherein said alternating firstand second surface features of said sensed element includesradially-inward extending projections, and the rotation sensor isextended radially to radially overlap with the radially-inward extendingprojections.